1. Technical Field
The present invention relates to a color filter ink, a color filter ink manufacturing method, a color filter ink set, a color filter, an image display device, and an electronic device.
2. Related Art
Color filters are generally used in liquid crystal display devices (LCD) and the like that display color.
Color filters have conventionally been manufactured using a so-called photolithography method in which a coating film composed of a material (color layer formation composition) that includes a colorant, a photosensitive resin, a functional monomer, a polymerization initiator, and other components is formed on a substrate, and then photosensitive processing for radiating light via a photomask, development processing, and the like are performed. In such a method, the color filters are usually manufactured by repeating a process in which a coating film corresponding to each color is formed on substantially the entire surface of the substrate, only a portion of the coating film is cured, and most of the film other than the cured portion is removed, so that there is no color overlap. Therefore, only a portion of the coating film formed in color filter manufacturing remains as a color layer in the finished color filter, and most of the coating film is removed in the manufacturing process. Therefore, not only does the manufacturing cost of the color filter increase, but the process is also undesirable from the perspective of resource saving.
Methods have recently been proposed for forming the color layer of a color filter through the use of an inkjet head (droplet discharge head) (see Japanese Laid-Open Patent Application No. 2004-2815, for example). In such a method, because the discharge position and the like of droplets of the material (color layer formation composition) used to form the color layer are easily controlled, and waste of the color layer formation composition can be reduced, the environmental impact can be reduced, and manufacturing cost can also be minimized.
However, in a color filter manufacturing method that uses an inkjet head (inkjet method), the formed color layer does not readily assume a flat shape, and as a result, the color filter has inadequate contrast ratio and brightness. A color filter manufactured using an inkjet method is also generally subjected to heat treatment and cleaning by a solvent or the like in the manufacturing process. Thermal resistance, solvent resistance, and other durability characteristics are therefore required in the color filter manufactured using an inkjet method, but satisfactory durability is difficult to obtain in the conventional color filter.